1. Technical Field
The present invention relates to a method for estimating acoustic velocity of an ultrasonic image and an ultrasonic diagnosis apparatus using the same.
2. Description of the Related Art
An ultrasonic diagnosis apparatus is one of the most important diagnosis apparatuses, which are being used in various fields. In particular, the ultrasonic diagnosis apparatus has been widely used in the medical field due to its noninvasive and nondestructive characteristics to objects. Recently, a high-performance ultrasonic system is used to generate 2-dimensional or 3-dimensional images of the inside of objects.
Generally, the ultrasonic diagnosis apparatus receives echo waves obtained by reflecting a part of the ultrasonic waves transmitted from an ultrasonic probe from a change point (change surface) of a tissue structure in an object and generates a tomographic image of an object based on the echo waves.
The generated ultrasonic image can be generated by propagating ultrasonic waves emitted from the ultrasonic probe to the tissue of the object and collecting reflected waves (echo waves) which are returned by being reflected from the tissue.
In the prior art, the ultrasonic diagnosis apparatus generates the ultrasonic images by operating the above-mentioned processes in order to diagnose the tissue in the human body. In this case, the ultrasonic diagnosis apparatus focuses beams under the assumption that the ultrasonic diagnosis apparatus has the same acoustic velocity (for example, about 1540 m/s) in all the regions of the tissue in the human body. However, the tissue in the human body has inherent acoustic velocity according to each vehicle.
For this reason, a difference between the real acoustic velocities of each tissue in the human body and the assumed acoustic velocities may be generated. The difference may have an effect on the reflected wave returned by being reflected from each tissue in the human body.
Therefore, as the difference between the real acoustic velocities in different types of tissue of the human body and the assumed acoustic velocities is increased, the difference between the reflected waves may also be increased. As a result, the beams reflected from the tissue in the human body become defocused, which causes a problem of degrading resolution and tissue contrast by distorting images.
Therefore, in order to obtain higher-definition ultrasonic images for a more accurate diagnosis, there is a need to more rapidly and accurately estimate the real acoustic velocities of each part of the human body and apply them to the ultrasonic diagnosis apparatus.